public class p82_4 {
	public static void main(String args[]) {
	p82_1 circle=new p82_1();
	circle.setRadius(196.87);
	p82_2 lader=new p82_2(3,21,9);
	p82_3 zhang=new p82_3();
	System.out.println("zhang计算圆的面积:");
	double result=zhang.computerArea(circle);
	System.out.println(result);
	System.out.println("zhang计算梯形面积:");
	result=zhang.computerArea(lader);
	System.out.println(result);
	}
}
